Monolithic segmented led array architecture

ABSTRACT

A first component with a first sidewall and a second component with a second sidewall may be mounted onto an expandable film such that an original distance X is the distance between the first sidewall and the second sidewall. The expandable film may be expanded such that an expanded distance Y is the distance between the first sidewall and the second sidewall and expanded distance Y is greater than original distance X. A first sidewall material may be applied within at least a part of a space between the first sidewall and the second sidewall. The expandable film may be expanded such that a contracted distance Z is the distance between the first sidewall and the second sidewall, and contracted distance Z is less than expanded distance Y.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/226,604 filed Dec. 19, 2018 (now U.S. Pat. No. 11,355,548), whichclaims (i) benefit of U.S. Provisional Application No. 62/608,516 filedDec. 20, 2017 and (ii) priority of Application No. EP 18158961.5 filedFeb. 27, 2018; each of those applications is incorporated by referenceas if set forth herein in its entirety.

BACKGROUND

Precision control lighting applications can require the production andmanufacturing of small addressable light emitting diode (LED) pixelsystems. The smaller size of such pixel systems may requirenon-conventional components and manufacturing processes.

Semiconductor light-emitting devices including LEDs, resonant cavitylight emitting diodes (RCLEDs), vertical cavity laser diodes (VCSELs),and edge emitting lasers are among the most efficient light sourcesavailable. Materials systems of interest in the manufacture ofhigh-brightness light emitting devices capable of operation across thevisible spectrum include Group III-V semiconductors, particularlybinary, ternary, and quaternary alloys of gallium, aluminum, indium, andnitrogen, also referred to as III-nitride materials. III-nitride lightemitting devices can be fabricated by epitaxially growing a stack ofsemiconductor layers of different compositions and dopant concentrationson a sapphire, silicon carbide, III-nitride, composite, or othersuitable substrate by metal-organic chemical vapor deposition (MOCVD),molecular beam epitaxy (MBE), or other epitaxial techniques. The stackoften includes one or more n-type layers doped with, for example, Si,formed over the substrate, one or more light emitting layers in anactive region formed over the n-type layer or layers, and one or morep-type layers doped with, for example, Mg, formed over the activeregion. Electrical contacts are formed on the n- and p-type regions.

III-nitride devices are often formed as inverted or flip chip devices,where both the n- and p-contacts formed on the same side of thesemiconductor structure, and most of the light is extracted from theside of the semiconductor structure opposite the contacts.

SUMMARY

In accordance with an aspect of the disclosed subject matter, a firstcomponent with a first sidewall and a second component with a secondsidewall may be mounted onto an expandable film such that an originaldistance X is the distance between the first sidewall and the secondsidewall. The expandable film can be expanded such that an expandeddistance Y is the distance between the first sidewall and the secondsidewall and expanded distance Y is greater than original distance X. Afirst sidewall material may be applied within at least a part of a spacebetween the first sidewall and the second sidewall and the expandablefilm may be contracted such that a contracted distance Z is the distancebetween the first sidewall and the second sidewall, and contracteddistance Z is less than expanded distance Y.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1A is a top view illustration of a micro LED array with an explodedportion;

FIG. 1B is a cross sectional illustration of a pixel matrix withtrenches;

FIG. 10 is a perspective illustration of another pixel matrix withtrenches;

FIG. 1D is a flowchart for mounting components, with sidewall material,onto closely configured layers;

FIG. 1 E is a top view diagram showing the stages of an expandable film;

FIG. 1F is a flowchart for mounting wavelength converting layers ontoclosely configured layers;

FIG. 1G is a top view diagram showing the stages of another expandablefilm;

FIG. 1H is a cross sectional view diagram showing the stages of anexpandable film;

FIGS. 1I-1L are diagrams of sidewall material deposited betweencomponents;

FIG. 1M is a diagram showing a thickness pattern on an expandable film;

FIG. 1N is a diagram showing light emitter structures mounted onto alight emitting device;

FIG. 2A is a top view of the electronics board with LED array attachedto the substrate at the LED device attach region in one embodiment;

FIG. 2B is a diagram of one embodiment of a two channel integrated LEDlighting system with electronic components mounted on two surfaces of acircuit board;

FIG. 2C is an example vehicle headlamp system; and

FIG. 3 shows an example illumination system.

DETAILED DESCRIPTION

Examples of different light illumination systems and/or light emittingdiode (“LED”) implementations will be described more fully hereinafterwith reference to the accompanying drawings. These examples are notmutually exclusive, and features found in one example may be combinedwith features found in one or more other examples to achieve additionalimplementations. Accordingly, it will be understood that the examplesshown in the accompanying drawings are provided for illustrativepurposes only and they are not intended to limit the disclosure in anyway. Like numbers refer to like elements throughout.

It will be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms may be used todistinguish one element from another. For example, a first element maybe termed a second element and a second element may be termed a firstelement without departing from the scope of the present invention. Asused herein, the term “and/or” may include any and all combinations ofone or more of the associated listed items.

It will be understood that when an element such as a layer, region, orsubstrate is referred to as being “on” or extending “onto” anotherelement, it may be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there may be no intervening elements present. Itwill also be understood that when an element is referred to as being“connected” or “coupled” to another element, it may be directlyconnected or coupled to the other element and/or connected or coupled tothe other element via one or more intervening elements. In contrast,when an element is referred to as being “directly connected” or“directly coupled” to another element, there are no intervening elementspresent between the element and the other element. It will be understoodthat these terms are intended to encompass different orientations of theelement in addition to any orientation depicted in the figures.

Relative terms such as “below,” “above,” “upper,”, “lower,” “horizontal”or “vertical” may be used herein to describe a relationship of oneelement, layer, or region to another element, layer, or region asillustrated in the figures. It will be understood that these terms areintended to encompass different orientations of the device in additionto the orientation depicted in the figures.

Semiconductor light emitting devices (LEDs) or optical power emittingdevices, such as devices that emit ultraviolet (UV) or infrared (IR)optical power, are among the most efficient light sources currentlyavailable. These devices (hereinafter “LEDs”), may include lightemitting diodes, resonant cavity light emitting diodes, vertical cavitylaser diodes, edge emitting lasers, or the like. Due to their compactsize and lower power requirements, for example, LEDs may be attractivecandidates for many different applications. For example, they may beused as light sources (e.g., flash lights and camera flashes) forhand-held battery-powered devices, such as cameras and cell phones. Theymay also be used, for example, for automotive lighting, heads up display(HUD) lighting, horticultural lighting, street lighting, torch forvideo, general illumination (e.g., home, shop, office and studiolighting, theater/stage lighting and architectural lighting), augmentedreality (AR) lighting, virtual reality (VR) lighting, as back lights fordisplays, and IR spectroscopy. A single LED may provide light that isless bright than an incandescent light source, and, therefore,multi-junction devices or arrays of LEDs (such as monolithic LED arrays,micro LED arrays, etc.) may be used for applications where morebrightness is desired or required.

According to embodiments of the disclosed subject matter, LED arrays(e.g., micro LED arrays) may include an array of pixels as shown inFIGS. 1A, 1B, and/or 10. LED arrays may be used for any applicationssuch as those requiring precision control of LED array segments. Pixelsin an LED array may be individually addressable, may be addressable ingroups/subsets, or may not be addressable. In FIG. 1A, a top view of aLED array 110 with pixels 111 is shown. An exploded view of a 3×3portion of the LED array 110 is also shown in FIG. 1A. As shown in the3×3 portion exploded view, LED array 110 may include pixels 111 with awidth w₁ of approximately 100 μm or less (e.g., 40 μm). The lanes 113between the pixels may be separated by a width, w₂, of approximately 20μm or less (e.g., 5 μm). The lanes 113 may provide an air gap betweenpixels or may contain other material, as shown in FIGS. 1B and 1C andfurther disclosed herein. The distance d₁ from the center of one pixel111 to the center of an adjacent pixel 111 may be approximately 120 μmor less (e.g., 45 μm). It will be understood that the widths anddistances provided herein are examples only, and that actual widthsand/or dimensions may vary.

It will be understood that although rectangular pixels arranged in asymmetric matrix are shown in FIGS. 1A, B and C, pixels of any shape andarrangement may be applied to the embodiments disclosed herein. Forexample, LED array 110 of FIG. 1A may include, over 10,000 pixels in anyapplicable arrangement such as a 100×100 matrix, a 200×50 matrix, asymmetric matrix, a non-symmetric matrix, or the like. It will also beunderstood that multiple sets of pixels, matrixes, and/or boards may bearranged in any applicable format to implement the embodiments disclosedherein.

FIG. 1B shows a cross section view of an example LED array 1000. Asshown, the pixels 1010, 1020, and 1030 correspond to three differentpixels within an LED array such that a separation sections 1041 and/orn-type contacts 1040 separate the pixels from each other. According toan embodiment, the space between pixels may be occupied by an air gap.As shown, pixel 1010 includes an epitaxial layer 1011 which may be grownon any applicable substrate such as, for example, a sapphire substrate,which may be removed from the epitaxial layer 1011. A surface of thegrowth layer distal from contact 1015 may be substantially planar or maybe patterned. A p-type region 1012 may be located in proximity to ap-contact 1017. An active region 1021 may be disposed adjacent to then-type region and a p-type region 1012. Alternatively, the active region1021 may be between a semiconductor layer or n-type region and p-typeregion 1012 and may receive a current such that the active region 1021emits light beams. The p-contact 1017 may be in contact with SiO2 layers1013 and 1014 as well as metal layer 1016 (e.g., plated copper). The ntype contacts 1040 may include an applicable metal such as Cu. The metallayer 1016 may be in contact with a contact 1015 which may bereflective.

Notably, as shown in FIG. 1B, the n-type contact 1040 may be depositedinto trenches 1130 created between pixels 1010, 1020, and 1030 and mayextend beyond the epitaxial layer. Separation sections 1041 may separateall (as shown) or part of a converter material 1050. It will beunderstood that a LED array may be implemented without such separationsections 1041 or the separation sections 1041 may correspond to an airgap. The separation sections 1041 may be an extension of the n-typecontacts 1040, such that, separation sections 1041 are formed from thesame material as the n-type contacts 1040 (e.g., copper). Alternatively,the separation sections 1041 may be formed from a material differentthan the n-type contacts 1040. According to an embodiment, separationsections 1041 may include reflective material. The material inseparation sections 1041 and/or the n-type contact 1040 may be depositedin any applicable manner such as, for example, but applying a meshstructure which includes or allows the deposition of the n-type contact1040 and/or separation sections 1041. Converter material 1050 may havefeatures/properties similar to wavelength converting layer 205 of FIG.2A. As noted herein, one or more additional layers may coat theseparation sections 1041. Such a layer may be a reflective layer, ascattering layer, an absorptive layer, or any other applicable layer.One or more passivation layers 1019 may fully or partially separate then-contact 1040 from the epitaxial layer 1011.

The epitaxial layer 1011 may be formed from any applicable material toemit photons when excited including sapphire, SiC, GaN, Silicone and maymore specifically be formed from a III-V semiconductors including, butnot limited to, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP,InAs, InSb, II-VI semiconductors including, but not limited to, ZnS,ZnSe, CdSe, CdTe, group IV semiconductors including, but not limited toGe, Si, SiC, and mixtures or alloys thereof. These examplesemiconductors may have indices of refraction ranging from about 2.4 toabout 4.1 at the typical emission wavelengths of LEDs in which they arepresent. For example, III-Nitride semiconductors, such as GaN, may haverefractive indices of about 2.4 at 500 nm, and III-Phosphidesemiconductors, such as InGaP, may have refractive indices of about 3.7at 600 nm. Contacts coupled to the LED device 200 may be formed from asolder, such as AuSn, AuGa, AuSi or SAC solders.

The n-type region may be grown on a growth substrate and may include oneor more layers of semiconductor material that include differentcompositions and dopant concentrations including, for example,preparation layers, such as buffer or nucleation layers, and/or layersdesigned to facilitate removal of the growth substrate. These layers maybe n-type or not intentionally doped, or may even be p-type devicelayers. The layers may be designed for particular optical, material, orelectrical properties desirable for the light emitting region toefficiently emit light. Similarly, the p-type region 1012 may includemultiple layers of different composition, thickness, and dopantconcentrations, including layers that are not intentionally doped, orn-type layers. An electrical current may be caused to flow through thep-n junction (e.g., via contacts) and the pixels may generate light of afirst wavelength determined at least in part by the bandgap energy ofthe materials. A pixel may directly emit light (e.g., regular or directemission LED) or may emit light into a wavelength converting layer 1050(e.g., phosphor converted LED, “POLED”, etc.) that acts to furthermodify wavelength of the emitted light to output a light of a secondwavelength.

Although FIG. 1B shows an example LED array 1000 with pixels 1010, 1020,and 1030 in an example arrangement, it will be understood that pixels inan LED array may be provided in any one of a number of arrangements. Forexample, the pixels may be in a flip chip structure, a verticalinjection thin film (VTF) structure, a multi-junction structure, a thinfilm flip chip (TFFC), lateral devices, etc. For example, a lateral LEDpixel may be similar to a flip chip LED pixel but may not be flippedupside down for direct connection of the electrodes to a substrate orpackage. A TFFC may also be similar to a flip chip LED pixel but mayhave the growth substrate removed (leaving the thin film semiconductorlayers un-supported). In contrast, the growth substrate or othersubstrate may be included as part of a flip chip LED.

The wavelength converting layer 1050 may be in the path of light emittedby active region 1021, such that the light emitted by active region 1021may traverse through one or more intermediate layers (e.g., a photoniclayer). According to embodiments, wavelength converting layer 1050 ormay not be present in LED array 1000. The wavelength converting layer1050 may include any luminescent material, such as, for example,phosphor particles in a transparent or translucent binder or matrix, ora ceramic phosphor element, which absorbs light of one wavelength andemits light of a different wavelength. The thickness of a wavelengthconverting layer 1050 may be determined based on the material used orapplication/wavelength for which the LED array 1000 or individual pixels1010, 1020, and 1030 is/are arranged. For example, a wavelengthconverting layer 1050 may be approximately 20 μm, 50 μm or 200 μm. Thewavelength converting layer 1050 may be provided on each individualpixel, as shown, or may be placed over an entire LED array 1000.

Primary optic 1022 may be on or over one or more pixels 1010, 1020,and/or 1030 and may allow light to pass from the active region 101and/or the wavelength converting layer 1050 through the primary optic.Light via the primary optic may generally be emitted based on aLambertian distribution pattern such that the luminous intensity of thelight emitted via the primary optic 1022, when observed from an idealdiffuse radiator, is directly proportional to the cosine of the anglebetween the direction of the incident light and the surface normal. Itwill be understood that one or more properties of the primary optic 1022may be modified to produce a light distribution pattern that isdifferent than the Lambertian distribution pattern.

Secondary optics which include one or both of the lens 1065 andwaveguide 1062 may be provided with pixels 1010, 1020, and/or 1030. Itwill be understood that although secondary optics are discussed inaccordance with the example shown in FIG. 1B with multiple pixels,secondary optics may be provided for single pixels. Secondary optics maybe used to spread the incoming light (diverging optics), or to gatherincoming light into a collimated beam (collimating optics). Thewaveguide 1062 may be coated with a dielectric material, a metallizationlayer, or the like and may be provided to reflect or redirect incidentlight. In alternative embodiments, a lighting system may not include oneor more of the following: the wavelength converting layer 1050, theprimary optics 1022, the waveguide 1062 and the lens 1065.

Lens 1065 may be formed form any applicable transparent material suchas, but not limited to SiC, aluminum oxide, diamond, or the like or acombination thereof. Lens 1065 may be used to modify the a beam of lightto be input into the lens 1065 such that an output beam from the lens1065 will efficiently meet a desired photometric specification.Additionally, lens 1065 may serve one or more aesthetic purpose, such asby determining a lit and/or unlit appearance of the multiple LED devices200B.

FIG. 10 shows a cross section of a three dimensional view of a LED array1100. As shown, pixels in the LED array 1100 may be separated bytrenches which are filled to form n-contacts 1140. The pixels may begrown on a substrate 1114 and may include a p-contact 1113, a p-GaNsemiconductor layer 1112, an active region 1111, and an n-Gansemiconductor layer 1110. It will be understood that this structure isprovided as an example only and one or more semiconductor or otherapplicable layers may be added, removed, or partially added or removedto implement the disclosure provided herein. A converter material 1117may be deposited on the semiconductor layer 1110 (or other applicablelayer).

Passivation layers 1115 may be formed within the trenches 1130 andn-contacts 1140 (e.g., copper contacts) may be deposited within thetrenches 1130, as shown. The passivation layers 1115 may separate atleast a portion of the n-contacts 1140 from one or more layers of thesemiconductor. According to an implementation, the n-contacts 1140, orother applicable material, within the trenches may extend into theconverter material 1117 such that the n-contacts 1140, or otherapplicable material, provide complete or partial optical isolationbetween the pixels.

According to embodiments of the disclosed subject matter, an expandablefilm may be configured to expand the space between components (e.g.,wavelength converting layers, dies, etc.) that are mounted onto theexpandable tape, resulting in expanded lanes between the convertercomponents. The expanded lanes may enable application of one or moresidewall material such as spacer material or optical isolationmaterials, or one or more additional components (e.g., one or morewavelength converting layers with the same or different properties asthe wavelength converting layers already on the expandable film). Aspacer material may be any applicable material configured to separatetwo or more components and may enable the separation to allow alignmentwith light emitting devices, as disclosed herein. Optical isolationmaterial may be distributed Bragg reflector (DBR) layers, reflectivematerial, absorptive material, or the like. The sidewall materials maybe applied to one or more sidewalls of the components or may bedeposited within the lanes such that they at least partially take theform of the expanded lanes. Alternatively or in addition, one or morecomponents may be deposited within the lanes. The expandable film maythen be contracted, resulting in the expanded lanes contracting to asmaller width. The components along with all or a part of the sidewallmaterials may then be mounted onto a light emitting device such as, butnot limited to gallium nitride (GaN) mesas, LEDs, light active material,conductors, or the like.

It will be understood that although wavelength converting layers arespecifically used in some examples of this disclosure, any applicablecomponents (e.g., wavelength converting layer(s), semiconductorlayer(s), die(s), substrate(s), etc.) may be applied to a film that canexpand, in accordance with this disclosure.

Wavelength converting layers may contain, but are not limited to, one ormore applicable luminescent or optically scattering material such asphosphor particles or other particles as previously disclosed herein.

FIG. 1D shows a flow chart 1200 with steps to apply sidewall material tosidewalls and/or within lanes of small addressable LED pixel systems.

According to an embodiment of the disclosed subject matter, at step 1201of FIG. 1D, as also shown via a top view in FIG. 1E, a plurality ofcomponents 1340 may be mounted on an un-expanded expandable film 1310.For clarity, FIG. 1E shows the same expandable film in three differentstates. 1310 shows the expandable film in an un-expanded state, 1320shows the expandable film in an expanded state and 1330 shows theexpandable film after it has been expanded and contracted. As discussedbelow, the contracted expandable film 1330 may contract to the same sizeas the expandable film 1310 prior to being expanded or may contract to adifferent size.

The plurality of components 1340 may be mounted using any applicabletechnique such as bonding via adhesive, micro-connectors, or one or morephysical connector. As an example, an adhesive may be applied using aspin-on process. The expandable film may be a blue tape, a white tape, aUV tape, or any other suitable material that allows mounting to aflexible/expandable film. The distance w₅ between the lanes 1311 createdbetween components 1340 may be small, such as approximately 50 μm. In anembodiment, the distance of lanes 1311 may be 20 μm.

At step 1202 of FIG. 1D, as also shown in FIG. 1E the expandable film1310 may be expanded as shown by expandable film 1320. The expansion maybe an isotropic expansion such that the un-expanded expandable film 1310is expanded substantially linearly to the expanded state of theexpandable film 1320. As a non limiting example, the expansion may beisotropic such that a 20 μm expansion in the left direction may resultin the center of the film to shift 10 μm left and the expandable filmoverall to expand linearly by 20 μm. According to an embodiment of thedisclosed subject matter, the expandable film may expand in a non-linearmanner which may be pre-determined or detectible based on the resultingexpanded film 1320. As an example, a non-linear expansion may be onethat results in a greater amount of expansion towards the edges of theexpandable film and a lower amount of expansion towards the center. Asan alternate example, a non-linear expansion may be one that results ina greater amount of expansion where a mechanism that causes theexpansion is located. A mechanism that causes the expansion may be, forexample, via a heat source, a clamp, a pulling mechanism, or the like.As an example, the expandable film may be expanded via a thermochemicalexpansion which allows the film to expand based on gradually increasingthe temperature with high control fidelity. The film may contract whenthe temperature is lowered.

As shown in FIG. 1E, the distance between the components 1340 thatcreates the lanes 1311 may increase from the original distance w₅ on theun-expanded expandable film 1310 to a larger distance w₆ for lanes 1321.The distance w₆ may be sufficient to apply sidewall material to thesidewalls of the components 1340, as discussed herein.

At step 1203 of FIG. 1D, as also shown in FIG. 1E, sidewall material1350 may be applied within at least part of the expanded space betweencomponents 1340. The sidewall material may be any applicable spacermaterial or optical isolation material such as a distributed Braggreflector (DBR) layer(s), reflective material, absorptive material, orthe like. As specific examples, the sidewall material may includestainless steel or aluminum. DBR layers may include, but are not limitedto, layers of SiO₂ and TiO₂; SiO₂ and ZrO₂; SiC and MgO; SiC and Silica;GaAs and AlAs; ITO; or a-Si and a-Si. The amount of space w₆ between thewavelength converting layers 340 may allow the application of thesidewall material 1350.

At step 1204 of FIG. 1D, as also shown in FIG. 1E, the expandable filmmay be contracted as shown by expandable film 1330. The contraction mayresult in an isotropic contraction such that the contracted film 1330 iscontracted substantially linearly to the state of the contracted film1330. As a non limiting example, the contraction may be isotropic suchthat a 20 μm contraction towards the center may result in both the leftside and the right side of the film to contract by 10 μm towards thecenter and the expandable film overall to contract linearly. Accordingto an embodiment of the disclosed subject matter, the expandable filmmay contract in a non-linear manner which may be pre-determined ordetectible based on the resulting contracted film. As a non limitingexample, a non-linear contraction may be one that results in a greateramount of contraction by the top edges of the expandable film and alower amount of expand by the bottom edge of the expandable film. As analternate example, a non-linear contraction may be one that results in alower amount of contraction where a mechanism that caused the expansionis located.

It should be noted that the amount of space w₅ or w₇ between thecomponents 1340 that creates the lanes 1311 on the un-expandedexpandable film 1310 or the lanes 1331 in contracted expandable film1330 may not allow an application of sidewall material, as disclosedherein. As a specific non limiting example in reference to FIG. 1E, w₅may be 50 μm wide, w₆ may be 100 μm wide, and w₇ may be 20 μm wide. Inthis example, it should be noted that w₇ is less than w₅ (20 μm wide vs.50 μm wide) as, in this example, w₇ is calculated as the width betweenthe sidewall materials 1350 applied to the sidewalls of adjacentwavelength converting layers 1340.

An expandable film may be expanded to deposit one or more wavelengthconverting layers between wavelength converting layers placed on anunexpanded expandable film. The one or more wavelength converting layersto be placed may have the same properties (e.g., peak wavelengthemission, phosphor particle type, dimension, etc.) as the wavelengthconverting layers placed on the unexpanded expandable film.Alternatively or in addition, the one or more wavelength convertinglayers to be placed may allow for color variation such that the one ormore wavelength converting layers may have properties different than thewavelength converting layers placed on the unexpanded expandable film.FIG. 1F shows a flow chart 1300 with steps to apply one or morewavelength converting layers within lanes between originally placedwavelength converting layers, the lanes created by expanding theexpandable film, as disclosed herein.

According to an embodiment of the disclosed subject matter, at step 1301of FIG. 1F, as also shown via a top view in FIG. 1G, a plurality ofwavelength converting layers 1341 may be mounted on an un-expandedexpandable film 1310. For clarity, FIG. 1F shows the same expandablefilm in three different states. 1310 shows the expandable film in anun-expanded state, 1325 shows the expandable film in an expanded stateand 1335 shows the expandable film after it has been expanded andcontracted. As discussed below, the contracted expandable film 1335 maycontract to the same size as the expandable film 1310 prior to beingexpanded or may contract to a different size.

The plurality of wavelength converting layers 1341 may be mounted usingany applicable technique such as bonding via adhesive, micro-connectors,or one or more physical connector. As an example, an adhesive may beapplied using a spin-on process. The expandable film may be a blue tape,a white tape, a UV tape, or any other suitable material that allowsmounting to a flexible/expandable film. The distance w₅ between thelanes 1311 created between wavelength converting layers 1341 may besmall, such as approximately 50 μm. In an embodiment, the distance oflanes 1311 may be 20 μm.

At step 1302 of FIG. 1F, as also shown in FIG. 1G the expandable film1310 may be expanded as shown by expandable film 1325. The expansion maybe an isotropic expansion such that the un-expanded expandable film 1310is expanded substantially linearly to the expanded state of theexpandable film 1320. As a non limiting example, the expansion may beisotropic such that a 100 μm expansion in the left direction may resultin the center of the film to shift 50 μm left and the expandable filmoverall to expand linearly by 100 μm. According to an embodiment of thedisclosed subject matter, the expandable film may expand in a non-linearmanner which may be pre-determined or detectible based on the resultingexpanded film 1325. As an example, a non-linear expansion may be onethat results in a greater amount of expansion towards the edges of theexpandable film and a lower amount of expansion towards the center. Asan alternate example, a non-linear expansion may be one that results ina greater amount of expansion where a mechanism that causes theexpansion is located. A mechanism that causes the expansion may be, forexample, via a heat source, a clamp, a pulling mechanism, or the like.As an example, the expandable film may be expanded via a thermochemicalexpansion which allows the film to expand based on gradually increasingthe temperature with high control fidelity. The film may contract whenthe temperature is lowered.

As shown in FIG. 1G, the distance between the components 1340 thatcreates the lanes 1311 may increase from the original distance w₅ on theun-expanded expandable film 1310 to a larger distance w₅ for lanes 1326.The distance w₅ may be sufficient to apply one or more additionalwavelength converting layers, as discussed herein.

At step 1303 of FIG. 1F, as also shown in FIG. 1G, one or moreadditional wavelength converting layers 1342 and 1343 may be appliedwithin at least part of the expanded space between wavelength convertinglayers 1341. The additional wavelength converting layers may be the sameas or similar to the wavelength converting layers 1341 or may bedifferent than the wavelength converting layers 1341. According to anexample, wavelength converting layers 1341 may be configured to emit ared peak wavelength, wavelength converting layers 1342 may be configuredto emit a green peak wavelength, and wavelength converting layers 1343may be configured to emit a blue peak wavelength.

According to an embodiment, the expandable film 1310 may be expanded ina first direction, such as horizontally in FIG. 1G, such that a firsttype of wavelength converting layers 1342 is deposited in the spacecreated by the horizontal expansion. The expandable film may be expandedin a second direction, such as vertically in FIG. 1G, such that a secondtype of wavelength converting layer 1343 is deposited in the spacecreated by the vertical expansion. The expansion in the first directionand in the second direction may occur at the same time or may occur in asequence.

At step 1304 of FIG. 1F, as also shown in FIG. 1G, the expandable filmmay be contracted, as shown by expandable film 1335. The contraction mayresult in an isotropic contraction such that the contracted film 1335 iscontracted substantially linearly to the state of the contracted film1335. As a non limiting example, the contraction may be isotropic suchthat a 20 μm contraction towards the center may result in both the leftside and the right side of the film to contract by 10 μm towards thecenter and the expandable film overall to contract linearly. Accordingto an embodiment of the disclosed subject matter, the expandable filmmay contract in a non-linear manner which may be pre-determined ordetectible based on the resulting contracted film. As a non limitingexample, a non-linear contraction may be one that results in a greateramount of contraction by the top edges of the expandable film and alower amount of expand by the bottom edge of the expandable film. As analternate example, a non-linear contraction may be one that results in alower amount of contraction where a mechanism that caused the expansionis located.

It should be noted that the amount of space w₅ or w₉ between thewavelength converting layers 1341 that creates the lanes 1311 on theun-expanded expandable film 1310 or the lanes 1333 in contractedexpandable film 1335 may not allow an application of wavelengthconverting layers, as disclosed herein. As a specific non limitingexample in reference to FIG. 1G, w₅ may be 50 μm wide, w₈ may be 140 μmwide, and w₉ may be 10 μm wide. In this example, it should be noted thatw₉ is less than w₆ (10 μm wide vs. 50 μm wide).

FIG. 1H shows a cross-sectional view of the expanded expandable film1320 and the collapsed expandable film 1330. As shown in FIG. 1H, theexpanded expandable film 1320 allows for a wide lane with a width of w₆.When collapsed, expandable film 1330 contracts such that the lane widthbetween the wavelength converting layers 1340 with a sidewall material1350 is reduced to w₇ which is less than the wider width w₆.

According to an embodiment disclosed herein, as show in FIG. 1I,mounting components 1511 onto an expandable film 1510, expanding theexpandable film, applying sidewall materials 1512 to the sidewalls ofthe components 1511, and collapsing the expandable film 1510 may resultin a narrow lane 1520 between two adjacent sidewall materials 1512. As anon-limiting example, such a narrow lane 1520 may be present if thesidewall materials 1512 are DBR layers applied to the sidewalls of theadjacent components 1511. The narrow lane may have a width such that itallows the spacing between the components 1511 to align components 1511for mounting onto a light emitting device, as disclosed herein in step1204 of FIG. 1D. Specifically, the width of the narrow lane may enablecomponents 1511 to be positioned directly opposite their respectivelight emitting device so that a plurality of wavelength convertinglayers on an expandable film may be mounted onto a plurality of lightemitting devices substantially simultaneously. A visual representationof this alignment is shown in FIG. 1N.

According to an embodiment disclosed herein, as show in FIG. 1J,mounting components 1511 onto an expandable film, expanding theexpandable film, applying sidewall materials 1513 within the lanescreated between adjacent components 1511, and collapsing the expandablefilm 1510 may result in a filled lane between two adjacent components1511. As a non-limiting example, such a filled lane may be present ifthe sidewall material 1513 is an absorptive material or a reflectivematerial. The absorptive or reflective material may be poured into thelanes while the expandable film is expanded, such that it assumes theform of the lanes either while the expandable film is expanded or whenthe expandable film is collapsed. The filled lane may have a width suchthat it allows the filled spacing between the components 1511 to aligncomponents 1511 for mounting onto a light emitting device. Specifically,the width of the filled lane may enable respective components 1511 to bepositioned directly opposite their paired light emitting device so thata plurality of wavelength converting layers on an expandable film may bemounted onto a plurality of light emitting devices substantiallysimultaneously. A visual representation of this alignment is shown inFIG. 1N.

According to an embodiment disclosed herein, as show in FIG. 1K,mounting components 1511 onto an expandable film, expanding theexpandable film, applying sidewall materials 1512 and 513 within thelanes created between adjacent wavelength converting layers 511, andcollapsing the expandable film 510 may result in a filled lane betweentwo adjacent sidewall materials 512. According to this embodiment, afirst sidewall material 1512 may be applied to the sidewalls of adjacentwavelength converting layers and a second sidewall material 1513 may bepoured into the lanes between adjacent sidewall materials 1512. Both thesidewall materials 1512 and 1513 may be applied while the expandablefilm is expanded. As a specific non limiting example, the sidewallmaterial 1512 may be one or more DBR layers and may be applied directlyto the sidewalls of adjacent components 1511. The sidewall material 1513may be absorptive material or a reflective material. The absorptive orreflective material may be poured into the lanes while the expandablefilm is expanded, such that it assumes the form of the lanes eitherwhile the expandable film is expanded or when the expandable film iscollapsed. The combined width of the sidewall materials 1512 and 1513may allow the spacing between the components 1511 to align components1511 for mounting onto a light emitting device. Specifically, the widthof the sidewall materials 1512 and 1513 may enable respective components1511 to be positioned directly opposite their paired light emittingdevice so that a plurality of wavelength converting layers on anexpandable film may be mounted onto a plurality of light emittingdevices substantially simultaneously. A visual representation of thisalignment is shown in FIG. 1N.

According to an embodiment disclosed herein, as show in FIG. 1L,mounting components 1511 (e.g., wavelength converting layers) onto anexpandable film, expanding the expandable film, applying sidewallmaterials 1512 to the sidewalls of the components 1511, and collapsingthe expandable film 1510 may result in no space between adjacentsidewall materials 1512. As a non-limiting example, no space may bepresent if the sidewall materials 512 are DBR layers applied to thesidewalls of the adjacent components 1511. The adjacent sidewallmaterials 1512 may have a width such that the width allows the spacingbetween the components 1511 to align components 1511 for mounting onto alight emitting device. Specifically, the width of adjacent sidewallmaterials 1512 may enable respective components 1511 to be positioneddirectly opposite their paired light emitting device so that a pluralityof wavelength converting layers on an expandable film may be mountedonto a plurality of light emitting devices substantially simultaneously.A visual representation of this alignment is shown in FIG. 1N.

According to an embodiment of the disclosed subject matter, anexpandable film may expand or contract following an affine deformation.To reduce stress buildup on the expandable film, especially wherewavelength converting layers are located, an expandable film thicknesspattern may be implemented, as shown in FIG. 1M. An expandable film 1620may contain varying levels of thickness such as thicker sections 1621and thinner sections 1622. Wavelength converting layers 1610 may bemounted onto the thicker sections 1621 of the expandable film, as shownin the top block 1601, such that, when the expandable film is expandedor contracted, all or part of the added stress due to the mountedwavelength converting layers 1610 is compensated for and normalized, asa result of the added thickness of the thicker sections 1621.

The expanded expandable film is illustrated on the bottom block 1602 ofFIG. 1M. As shown, the thicker sections 1621 may substantially maintaintheir width, w₁₁, as the expandable film changes from an un-expandedstate to an expanded state. The thinner sections 1622 may experience amajority of the expanding and contracting, as shown by the difference inwidths w₉ and w₁₀. As shown, w12 is smaller than w₁₂. Here, w₁₁corresponds to the width of the thinner sections while the expandablefilm is un-expanded and w₁₂ corresponds to the width of the thinnersections when the expandable film is expanded. According to anembodiment, the thicker sections of an expandable film are at leasttwice as thick as the thinner sections of an expandable film.

According to an embodiment and as also shown in FIG. 1M, the surfacearea of the side of the wavelength converting layers 1610 that is incontact with the expandable film may be larger than the surface area ofthe thicker sections 1621 of the expandable film onto which thewavelength converting layers 1610 are mounted.

It will be understood that although square and/or rectangular patternsare described to represent the thicker and thinner portions of anexpandable film, any applicable pattern that allows for a thickersection and a thinner section of an expandable film may be implemented.Such patterns can include, but are not limited to, circular features,elliptical features, crosses, non-symmetric features and the like.

According to an embodiment, a collapsible film is disclosed such thatone or more components are placed on the collapsible film and, onceplaced, the film is collapsed to reduce the space between thecomponents. According to this embodiment, sidewall material may be addedbefore the collapsible film is collapsed such that once the collapsiblefilm is collapsed, there may not be enough space between components toadd sidewall material.

As shown in FIG. 1N, wavelength converting layers 1720 may be attachedto light emitting devices 1770 of an LED array 1700, to create pixels1775. In FIG. 1N, light emitting devices 1770 may include GaN layer1750, active region 1790, one or more contacts 1780, pattern sapphiresubstrate (PSS) 1760, and wavelength converting layers 1720. Thewavelength converting layers 1720 are shown on a contracted expandablefilm 1710, in accordance with the subject matter disclosed herein. Thecontracted expandable film 1710 may be contracted such that the distancebetween the wavelength converting layers 1720 enables the wavelengthconverting layers 1720 to align with the light emitting devices 1770 andto be attached to the light emitting devices 1770. More specifically,the spacing created between the wavelength converting layers 1720 duringthe expansion of the expandable film 1710, the application of a sidelayer material or additional wavelength converting layers 1720, and thecontraction of the expandable film 1710 may allow the wavelengthconverting layers 1720 to be mounted onto the light emitting devices1770.

As shown in FIG. 1N, sidewall materials 1730 may be applied to thewavelength converting layers 1720. The wavelength converting layers 1720may be mounted over GaN layers 1750 and pattern sapphire substrate (PSS)patterns 1760 may be located between the GaN layers 1750 and thewavelength converting layers. Active regions 1790 may be configured toemit light at least partially towards the wavelength converting layers1720 and the light emitting devices 1770 may include contacts 1780.Optical isolator material 1740 may be applied to the sidewalls of theGaN layer 1750. The expandable film 1710 may be removed from thewavelength converting layers 1720, for example, after the wavelengthconverting layers 1720 have been attached to the light emitting devices1770.

As an example, the pixels 1775 of FIG. 1N may correspond to the pixels111 of FIG. 1A-C. Specifically, as shown in FIG. 1A, the pixels 111 maycorrespond to the pixels 1775 of FIG. 1N after the wavelength convertinglayers 1720 are mounted onto the light emitting devices 1770. When thepixels 111 or 1775 are activated, the respective active regions 1790 ofthe emitters may generate a light. The light may pass through thewavelength converting layers 1720 and may substantially be emitted fromthe surface of the pixels 1775 (after the expandable film 1710 has beenremoved) and light that reaches the sidewalls of the wavelengthconverting layers 1720 may not escape from the sidewalls due to thesidewall materials 1730 and may be reflected when it intersects thesidewalls due to the sidewall materials 1730.

FIG. 2A is a top view of an electronics board with an LED array 410attached to a substrate at the LED device attach region 318 in oneembodiment. The electronics board together with the LED array 410represents an LED system 400A. Additionally, the power module 312receives a voltage input at Vin 497 and control signals from theconnectivity and control module 316 over traces 4188, and provides drivesignals to the LED array 410 over traces 418A. The LED array 410 isturned on and off via the drive signals from the power module 312. Inthe embodiment shown in FIG. 2A, the connectivity and control module 316receives sensor signals from the sensor module 314 over trace 4180. Thepixels 1775 of FIG. 1N may correspond to the in the pixels in the LEDarray 410 of FIG. 2A and may be manufactured in accordance with thetechniques disclosed in FIGS. 1D-1M.

FIG. 2B illustrates one embodiment of a two channel integrated LEDlighting system with electronic components mounted on two surfaces of acircuit board 499. As shown in FIG. 2B, an LED lighting system 400Bincludes a first surface 445A having inputs to receive dimmer signalsand AC power signals and an AC/DC converter circuit 412 mounted on it.The LED system 400B includes a second surface 445B with the dimmerinterface circuit 415, DC-DC converter circuits 440A and 440B, aconnectivity and control module 416 (a wireless module in this example)having a microcontroller 472, and an LED array 410 mounted on it. TheLED array 410 is driven by two independent channels 411A and 411B. Inalternative embodiments, a single channel may be used to provide thedrive signals to an LED array, or any number of multiple channels may beused to provide the drive signals to an LED array.

The LED array 410 may include two groups of LED devices. In an exampleembodiment, the LED devices of group A are electrically coupled to afirst channel 411A and the LED devices of group B are electricallycoupled to a second channel 411B. Each of the two DC-DC converters 440Aand 440B may provide a respective drive current via single channels 411Aand 411B, respectively, for driving a respective group of LEDs A and Bin the LED array 410. The LEDs in one of the groups of LEDs may beconfigured to emit light having a different color point than the LEDs inthe second group of LEDs. Control of the composite color point of lightemitted by the LED array 410 may be tuned within a range by controllingthe current and/or duty cycle applied by the individual DC/DC convertercircuits 440A and 440B via a single channel 411A and 411B, respectively.Although the embodiment shown in FIG. 2B does not include a sensormodule (as described in FIG. 2A), an alternative embodiment may includea sensor module.

The illustrated LED lighting system 400B is an integrated system inwhich the LED array 410 and the circuitry for operating the LED array410 are provided on a single electronics board. Connections betweenmodules on the same surface of the circuit board 499 may be electricallycoupled for exchanging, for example, voltages, currents, and controlsignals between modules, by surface or sub-surface interconnections,such as traces 431, 432, 433, 434 and 435 or metallizations (not shown).Connections between modules on opposite surfaces of the circuit board499 may be electrically coupled by through board interconnections, suchas vias and metallizations (not shown).

According to embodiments, LED systems may be provided where an LED arrayis on a separate electronics board from the driver and controlcircuitry. According to other embodiments, a LED system may have the LEDarray together with some of the electronics on an electronics boardseparate from the driver circuit. For example, an LED system may includea power conversion module and an LED module located on a separateelectronics board than the LED arrays.

According to embodiments, an LED system may include a multi-channel LEDdriver circuit. For example, an LED module may include embedded LEDcalibration and setting data and, for example, three groups of LEDs. Oneof ordinary skill in the art will recognize that any number of groups ofLEDs may be used consistent with one or more applications. IndividualLEDs within each group may be arranged in series or in parallel and thelight having different color points may be provided. For example, warmwhite light may be provided by a first group of LEDs, a cool white lightmay be provided by a second group of LEDs, and a neutral white light maybe provided by a third group.

FIG. 2C shows an example vehicle headlamp system 300 including a vehiclepower 302 including a data bus 304. A sensor module 307 may be connectedto the data bus 304 to provide data related to environment conditions(e.g. ambient light conditions, temperature, time, rain, fog, etc.),vehicle condition (parked, in-motion, speed, direction),presence/position of other vehicles, pedestrians, objects, or the like.The sensor module 307 may be similar to or the same as the sensor module314 of FIG. 2A. AC/DC Converter 305 may be connected to the vehiclepower 302. The pixels 1775 of FIG. 1N may correspond to the in thepixels in the active head lamp 330 of FIG. 2C and may be manufactured inaccordance with the techniques disclosed in FIGS. 1D-1M.

The power module 312 (AC/DC converter) of FIG. 2C may be the same as orsimilar to the AC/DC converter 412 of FIG. 2B and may receive AC powerfrom the vehicle power 302. It may convert the AC power to DC power asdescribed in FIG. 2B for AC-DC converter 412. The vehicle head lampsystem 300 may include an active head lamp 330 which receives one ormore inputs provided by or based on the AC/DC converter 305,connectivity and control module 306, and/or sensor module 307. As anexample, the sensor module 307 may detect the presence of a pedestriansuch that the pedestrian is not well lit, which may reduce thelikelihood that a driver sees the pedestrian. Based on such sensorinput, the connectivity and control module 306 may output data to theactive head lamp 330 using power provided from the AC/DC converter 305such that the output data activates a subset of LEDs in an LED arraycontained within active head lamp 330. The subset of LEDs in the LEDarray, when activated, may emit light in the direction where the sensormodule 307 sensed the presence of the pedestrian. These subset of LEDsmay be deactivated or their light beam direction may otherwise bemodified after the sensor module 207 provides updated data confirmingthat the pedestrian is no longer in a path of the vehicle that includesvehicle head lamp system.

FIG. 3 shows an example system 550 which includes an applicationplatform 560, LED systems 552 and 556, and optics 554 and 558. LEDsystem 552 and 556 may include LED arrays generated in accordance withthe techniques disclosed in FIGS. 1D-M. The LED System 552 produceslight beams 561 shown between arrows 561 a and 561 b. The LED System 556may produce light beams 562 between arrows 562 a and 562 b. In theembodiment shown in FIG. 3, the light emitted from LED System 552 passesthrough secondary optics 554, and the light emitted from the LED System556 passes through secondary optics 556. In alternative embodiments, thelight beams 561 and 562 do not pass through any secondary optics. Thesecondary optics may be or may include one or more light guides. The oneor more light guides may be edge lit or may have an interior openingthat defines an interior edge of the light guide. LED systems 552 and/or556 may be inserted in the interior openings of the one or more lightguides such that they inject light into the interior edge (interioropening light guide) or exterior edge (edge lit light guide) of the oneor more light guides. LEDs in LED systems 552 and/or 556 may be arrangedaround the circumference of a base that is part of the light guide.According to an implementation, the base may be thermally conductive.According to an implementation, the base may be coupled to aheat-dissipating element that is disposed over the light guide. Theheat-dissipating element may be arranged to receive heat generated bythe LEDs via the thermally conductive base and dissipate the receivedheat. The one or more light guides may allow light emitted by LEDsystems 552 and 556 to be shaped in a desired manner such as, forexample, with a gradient, a chamfered distribution, a narrowdistribution, a wide distribution, an angular distribution, or the like.

In example embodiments, the system 550 may be a mobile phone of a cameraflash system, indoor residential or commercial lighting, outdoor lightsuch as street lighting, an automobile, a medical device, AR/VR devices,and robotic devices. The LED System 400A shown in FIG. 2A and vehiclehead lamp system 300 shown in FIG. 2C illustrate LED systems 552 and 556in example embodiments.

The application platform 560 may provide power to the LED systems 552and/or 556 via a power bus via line 565 or other applicable input, asdiscussed herein. Further, application platform 560 may provide inputsignals via line 565 for the operation of the LED system 552 and LEDsystem 556, which input may be based on a user input/preference, asensed reading, a pre-programmed or autonomously determined output, orthe like. One or more sensors may be internal or external to the housingof the application platform 560. Alternatively or in addition, as shownin the LED system 400 of FIG. 2A, each LED System 552 and 556 mayinclude its own sensor module, connectivity and control module, powermodule, and/or LED devices.

In embodiments, application platform 560 sensors and/or LED system 552and/or 556 sensors may collect data such as visual data (e.g., LIDARdata, IR data, data collected via a camera, etc.), audio data, distancebased data, movement data, environmental data, or the like or acombination thereof. The data may be related a physical item or entitysuch as an object, an individual, a vehicle, etc. For example, sensingequipment may collect object proximity data for an ADAS/AV basedapplication, which may prioritize the detection and subsequent actionbased on the detection of a physical item or entity. The data may becollected based on emitting an optical signal by, for example, LEDsystem 552 and/or 556, such as an IR signal and collecting data based onthe emitted optical signal. The data may be collected by a differentcomponent than the component that emits the optical signal for the datacollection. Continuing the example, sensing equipment may be located onan automobile and may emit a beam using a vertical-cavitysurface-emitting laser (VCSEL). The one or more sensors may sense aresponse to the emitted beam or any other applicable input.

In example embodiment, application platform 560 may represent anautomobile and LED system 552 and LED system 556 may representautomobile headlights. In various embodiments, the system 550 mayrepresent an automobile with steerable light beams where LEDs may beselectively activated to provide steerable light. For example, an arrayof LEDs may be used to define or project a shape or pattern orilluminate only selected sections of a roadway. In an exampleembodiment, Infrared cameras or detector pixels within LED systems 552and/or 556 may be sensors (e.g., similar to sensors module 314 of FIG.2A and 307 of FIG. 2C) that identify portions of a scene (roadway,pedestrian crossing, etc.) that require illumination.

Having described the embodiments in detail, those skilled in the artwill appreciate that, given the present description, modifications maybe made to the embodiments described herein without departing from thespirit of the inventive concept. Therefore, it is not intended that thescope of the invention be limited to the specific embodimentsillustrated and described. Although features and elements are describedabove in particular combinations, one of ordinary skill in the art willappreciate that each feature or element can be used alone or in anycombination with the other features and elements. In addition, themethods described herein may be implemented in a computer program,software, or firmware incorporated in a computer-readable medium forexecution by a computer or processor. Examples of computer-readablemedia include electronic signals (transmitted over wired or wirelessconnections) and computer-readable storage media. Examples ofcomputer-readable storage media include, but are not limited to, a readonly memory (ROM), a random access memory (RAM), a register, cachememory, semiconductor memory devices, magnetic media such as internalhard disks and removable disks, magneto-optical media, and optical mediasuch as CD-ROM disks, and digital versatile disks (DVDs).

1. A method for forming a light emitting device, the method comprising:providing a conversion array of multiple wavelength conversionstructures mounted on a film that is expandable or contractable, eachwavelength conversion structure comprising a bottom surface attached tothe film, an oppositely positioned top surface, and sidewall surfacesconnecting the top and bottom surfaces, the sidewall surfaces of eachwavelength conversion structure mounted on the film being spaced apartfrom the sidewall surfaces of adjacent mounted wavelength conversionstructures of the conversion array; applying a first sidewall materialbetween each pair of adjacent sidewalls of the wavelength conversionstructures of the conversion array; positioning a light emitting array,that includes multiple light emitting semiconductor diodes structurespositioned on a common substrate, with the conversion structures and thediode structures between the film and the common substrate and withcorresponding light emitting surfaces of the diode structures facing thetop surfaces of corresponding wavelength conversion structures of theconversion array; and with the wavelength conversion structuresremaining attached to the film and with the diode structures on thecommon substrate, attaching to the light emitting surface of each lightemitting diode structure the top surface of a corresponding one of thewavelength conversion structures, and one or both of: before applyingthe first sidewall material, expanding the film to increase a gapdistance between each pair of adjacent sidewalls of adjacent wavelengthconversion structures of the conversion array; or after applying thefirst sidewall material, contracting the film to decrease the gapdistance between each pair of adjacent sidewalls of adjacent wavelengthconversion structures of the conversion array.
 2. The method of claim 1,wherein each wavelength conversion structures comprises a ceramicphosphor element or a plurality of phosphor particles in a transparentor translucent binder or matrix.
 3. The method of claim 1, wherein theexpandable film comprises a plurality of thick sections and a pluralitythin sections separating the thick sections from one another, with eachthick section having a height that is at least two times a height of thethin sections, and with each wavelength conversion structure beingmounted on a corresponding one of the thick sections.
 4. The method ofclaim 3, wherein a surface area of the bottom of each wavelengthconversion structure is larger than an area of the corresponding thicksection to which that wavelength conversion structure is mounted.
 5. Themethod of claim 1, wherein the first sidewall material includes one orboth of an optical isolation material or a spacer material.
 6. Themethod of claim 5, wherein the optical isolation material includes oneor more of a light absorptive material or a light reflective material.7. The method of claim 6, wherein the first sidewall material includes afirst distributed Bragg reflector (DBR) layer applied to a firstsidewall of each pair of adjacent sidewalls.
 8. The method of claim 7,further comprising applying a second sidewall material between adjacentsidewalls of the wavelength conversion structures of the conversionarray, the second sidewall material being applied between the first DBRlayer and a second sidewall of each pair of adjacent sidewalls.
 9. Themethod of claim 8, wherein the second sidewall material includes one ormore of (i) a light absorptive material, (ii) a light reflectivematerial, or (iii) a second distributed Bragg reflector (DBR) layer thatis applied to the second sidewall of each pair of adjacent sidewalls.10. The method of claim 8, wherein: the second sidewall materialincludes a second distributed Bragg reflector (DBR) layer that isapplied to the second sidewall of each pair of adjacent sidewalls, andafter attaching the wavelength conversion structures to the diodestructures, the gap distance is equal to a sum of (i) the thickness ofthe DBR layer applied to the first sidewall of each pair of adjacentsidewalls and (ii) the thickness of the DBR layer applied to the secondsidewall of each pair of adjacent sidewalls.
 11. The method of claim 1,wherein the film is expanded before applying the first sidewallmaterial.
 12. The method of claim 11, wherein the diode structures areattached to the wavelength conversion structures after expanding thefilm.
 13. The method of claim 1, wherein the film is contracted afterapplying the first sidewall material.
 14. The method of claim 13,wherein the diode structures are attached to the wavelength conversionstructures after contracting the film.
 15. The method of claim 1,wherein the film is expanded before applying the first sidewall materialand is contracted after applying the first sidewall material.
 16. Themethod of claim 15, wherein the gap distance before expanding the filmis equal to the gap distance after contracting the film.
 17. The methodof claim 1, wherein the diode structures are attached to the wavelengthconversion structures without altering the gap distance.
 18. The methodof claim 1, wherein the film is configured to expand or contract inresponse to adjustments of temperature of the film.
 19. The method ofclaim 1, wherein the film is configured to expand or contract eitherisotropically or nonlinearly.
 20. The method of claim 1, wherein thefilm is a thermally-releasable tape or a UV-releasable tape.